(py)-n-oxides of certain carbamates of 2-pyridinemethanol



United States Patent ABSTRACT OF THE DISCLOSURE (Py)-N-oxides of N-alkyL and N,N'-dialkylcarbamates and thioncarbamates of Z-pyridinemethanol were prepared, preferably from the N-oxide of Z-pyridinemethanol, and found in mammals to exhibit anti-inflammatory activity and to prevent passive cutaneous anaphylaxis. 2 pyridinemethanol N-methyl-carbamate (py)-N-oxide was a preferred compound.

Summary of the invention A compound having the formula wherein X is a member selected from the group consisting of oxygen and sulfur and R and R are each a member selected from the group consisting of hydrogen and (lower) alkyl.

Detailed description This invention relates to new synthetic compounds having valuable anti-inflammatory properties and, more particularly, to N-monoand di-alkyl car'bamates and thioncarbamates of pyridine alcohols and their (py)-N- oxides.

It was the object of the present invention to provide novel and nontoxic compounds which in mammals exhibit anti-inflammatory activity and prevent passive cutaneous anaphylaxis and which by their nature are free of the undesirable side-effects caused by the steroids generally used for such purposes. It was a further object of the present invention to provide nontoxic agents useful in the alleviation of the symptoms of such inflammatory processes as arthritis and purpura.

The objects of the present invention have been achieved by the provision according to the present invention, of a member selected from the group consisting of a compound of the formula:

R1 (crmtrdflodmmu Y wherein R and H are each a member selected from the group consisting of hydrogen and (lower)alkyl, R is a member selected from the group consisting of hydrogen, (lower)alkyl, aralkyl and a heterocyclic or heteroaromatic radical, X is a member selected from the group consisting of oxygen and sulfur, Y is a member selected from the group consisting of hydrogen, halogen, alkyl, hydroxyl, cyano, aldoxime, carboxyl, carboalkoxy and amidocarboxyl which may be monoor di-substituted with (lower) alkyl group and It means a number of from 3,409,625 Patented Nov. 5, 1968 2 0 to 4, and the group consisting of a compound of the formula f i (CHzh-CHONRR Y \N J, 0

wherein R R R X, Y and n have the same meaning set forth above; and nontoxic, pharmaceutically acceptable acid addition salts thereof, including salts with organic and inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, acetic acid, maleic acid, tartaric acid, citric acid, sulfamic acid, glycolic acid, succinic acid, ascorbic acid and the like.

Preferred embodiments of the present invention are the compounds of the formulae X 01120 g NR R Y X 15 CHzO R R Y and wherein R R forth above.

The compounds of the present invention are synthesized from alcohols of the structure or the (py)-N-oxide derivative of the compounds of Formula I in any one of five Ways, Le.

(a) The compound of the Formula I or its (py)-N- oxide is reacted with a compound represented -by the formula:

R2NCEX (II) or (b) The compound oxide is reacted with of the Formula I or its (py)-N- a compound represented by the (c) The compound of the Formula I or its (py)-N- oxide is reacted with phosgene or thiophosgene and then reacted with an amine represented by the formula:

R (IV) is converted by known processes to an azidoforrnate and then the azidoformate is reacted with the amine of the Formula IV. In the above Formulae I, II, III, and IV,

II k jR fxfYaiid'fi have the same meanings as described hereinbefore.

.Alternatively, (py)-N-oxide derivative of the abovem entioned pyridinealcohol carbamates and thioncarbamates can be also manufactured by the process, in which the compound of the Formula I is carbamoylated by the process (a), (b), (c), (d), or (e), and then the product is oxidized with inorganic or organic peroxide by the known processes.

In the embodiment of the process (a), the compound of the Formula I or its (py)N-oxide is reacted with one moleor an excess, especially 1.5 to 2 mole of the compauses 'of the Formula II in a solvent or diluent. The s'iiitable solvents or diluents are inactive solvents such as benzene, toluene, "chlorobenzene, acetonitrile, chloroform, tctfahydrofuran, or pyridine. The reaction is preferably carried out at a temperature of from room temperature to 150 C.', especially under 100 C. If necessary, a catalys't'su'c'h as tertiary amine, for example, trimethylamine triethylamine, N- lkylpiperidine, and pyridine may be used in the reaction. When an isothiocyanate as the compound of the Formula II is reacted, it is preferable to use alkali metal alkoxide such as potassium tert-butoxide as a catalyst. In place of the isocyanate of the Formula II, compounds which can the Formula II under the reaction conditions can be used and if necessary a catalyst to generate the isocyanate may be used. For example, acyl azide represented by the formula: R CON or S-alkyl thiolcarbamates represented by the formula: R NI-ICOS-a1kyl may be used under heating, and S-alkyl thiolcarbamates may be also used in the presence of trialkylamine and heav metal salt such as silver nitrate.

In the embodiment of the process (b), the compounds of the Formula I or its (py)N-oxide derivative is reacted with the functional derivatives of carboxylic acid represented by the Formula III. When the functional derivative is an acid chloride, that is Z=Cl, the reaction is carried out in a suitable solvent or diluent such as benzene, toluene, chlorobenzene, diethyl ether, pyridine, and chloroform. The other reaction conditions are similar to that described above in the process (a). On the other hand, when the functional derivative is an ester of acid, it is necessary to use a catalyst. As the catalyst, sulfuric acid,-toluenesulfonic acid, metal alkoxides, for example, aluminum isopropoxide and potassium tert-butoxide are preferable. As the solvent or diluent, benzene, toluene, chlorobenzene, and tetrahydrofuran are suitable. The reaction is carried out at a temperature of about the boiling point of the solvent or diluent. While the reaction proceeds, slow distillation of the solvent or diluent from the reaction system improves the yield of the objective prodnot.

In the embodiment of the process (c), the compound of the Formula I or its (py)-N-oxide derivative is dissolved or suspended in a solvent or diluent such as benzene, toluene,chlorobenzene, diethyl ether, diisopropyl ether, or chloroform. The solution or suspension is preferably added with tertiary amine, for example, dimethylaniline, diethylaniline, or pyridine as a catalyst or dehydrochlorinating agent and then added with phosgene and thereafter added with ammonia, monoalkylamine, or dialkylamine to effect the reaction. The reaction is effected at a room temperature or lower, particularly below C. In the embodiment of the process (d), the aryloxyformate ester which is represented by the formula:

. (CHi)u( JHOCO-Ar Y N wherein Ar means preferably phenyl group which may be substituted with a halogen atom, alkyl-, alkoxy-, or nitro-group or (py)-N-oxide derivative of the Formula V is reacted with the amine represented by the Formula IV be converted to the isocyanate of s 4 at a temperature drfrein" O to CIj'pieffably at around room temperature. he reaction can be effected in the presence or absence of solvents or diluents. As the solvent or diluent, methanol ethanol, and the other low molecular alcohols can,.be used. The arylforrnate ester of the Formula V or its (py;)-N-oxidederivative, which is necessary in the process (d), can be preparedeasily from the pyridinealcohol of:the, Formula Lorits (py )'N- oxide derivative by'known processes, for exa'mplei by reaction witharylchloroformateI In the embodiment of the process (e), azidoformat'e of the following general formul Q iqonnr-onooom \N wherein R Y and r have the samemeaning as described hereinbefore, is reacted with the amine r' presentedby the Formula IV at atemperatureof from 0 to 100 (3., preferably' at around room temperature. The reactior'rcan be effected in the presence or absence of: solvents ordiluents. The azidoformate, which is necessary in the process (e), can be prepared easily from the pyridinealcohol of the Formula I or its (py)-N-derivative by the known process: for example, the compound of the Formula I or its (py)- N-oxide derivative is converted to an arylor alkylformate by reaction with arylor alkylchloroformate, and the arylor alkylformate is converted to an ester of carbazinic acid by reaction with hydrazine, and then the ester of carbazinic acid is reacted with nitrous acid.

The (py)-N-oxide derivative of the pyridinealcohol carbamates and thioncarbamates can be: also manufactured by the process, in which the compound of the Formula I is carbarnoylated by the processes (a), (b), (c), (d), or (e), and then the product is oxidized with inorganicor organic peroxide by known processes. As the peroxid especially hydrogen peroxide is preferred and organic peracids such as monoperphthalic acid may also be used. When hydrogen peroxide is used, the combination of hydrogen peroxide-acetic acid is preferred, and the reaction is conducted at a temperature of from 60 to 100 C. When monoperphthalic acid is used, the combination of monoperphthalic acid-ether is preferred, and the reaction isconducted at around room temperature.

In the procedure of the process of the present invention, the products can be separated and purified by conventional methods as described hereinafter.

The pyridinemethanols used as reagents in the processes of the present invention are prepared most frequently from the esters of the corresponding pyridine carboxylic acids by reduction with a complex metal hydride, e. g. lithium aluminum hydride, di-isobutyl aluminum hydride, sodium borohydride) according to Mosher et al., J. Amer. Chem. Soc. 73, 4926 (1951).

In another procedure for obtaining substituted 2- or 4-pyridine methanols, the corresponding picoline is heated with 30% hydrogen peroxide in glacial acetic acid and then treated with acetic anhydride according to the directions of Boekelheide et al., J. Amer. Chem. Soc. 76, 1286-1291 (1954) to give the acetatefrom which the desired 2- or 4-pyridine methanol is obtained by hydrolysis with hydrochloric acid.

Alternatively, ketone and aldehyde derivatives of appropriately substituted pyridine are reduced by catalytic hydrogenation according to Panizzon, Helv. 'Chim. Acta., 24E, 24 (1941) and Mathes et al., Ber. 86, 584 (1953). Pyridinealdehydes are also reduced to pyridine-alcohols by aluminum isopropoxide reduction, as illustrated by the procedure of McDonald, J. Amer. Chem. Soc. 69, 1219 (1947). v

The term (lower)alkyl as used herein refers to straight and branched chain saturated monovalent aliphatic hydrocarbon radicals having from one to ten carbon atoms inclusive, eg methyl, ethyl, propyl, isopropyl,

1 per kg. once a day. A long term normal and isoand secondary and tertiary-butyl, amyl, decyl, etc. The preferred (lower)alkyl groups are those having from one to six carbon atoms.

The compounds of this invention are useful in the treatment of disease in animals, including particularly the higher animals such as man and horses, dogs, etc. The compounds are particularly useful in the treatment of infiammatory diseases, including rheumatic fever, purpura rheumatica and rheumatoid arthritis. The utility of the present compounds is enhanced by the absence of steroidal side effects.

The compounds are administered to the affected host in amounts ranging from 2 to 50 mg. per kilogram of body weight per day. The usual dosage is from about 5 to about 30 mg. per kg. per day. The compounds can be administered parenterally and, preferably, orally. The compounds can be orally administered in the conventional forms, i.e. as tablets, capsules, suspensions, etc. The compounds of this invention can be combined in one dosage form with other therapeutically effective agents, including analgesics and the steroids which have also been used in the treatment of inflammatory disease.

The present invention is illustrated but not limited by the following examples in which the parts used are parts by weight and all temperatures are given in degrees centigrade. In the examples, all the ultraviolet spectra (abbreviated by UV-spectra or spectrum) were measured in 95% ethanol solution, and in the infrared spectra, absorption maxima are shown in wave number (cmbut absorption peaks appearing in the range of 3000-2900 cm. were omitted.

Example 1 To a solution of 11 parts of 4-pyridinemethanol in 60 parts by volume of pyridine was added 8 parts of methylisocyanate. The solution was allowed to stand at room temperature for 12 hours and then heated for 2 hours at 100 C. The solvent was distilled off under reduced pressure, and then the resulting residue was distilled in vacuum to give 12 parts of 4-pyridinemethanol N-methylcarbamate boiling at 130135 C./ 4 mm. Hg. The picrate of the product melted at l48149 C.

Elemental analysis of the picrate: Calculated: C, 42.54%; H, 3.32%; N, 17.72%. Found: C, 42.36%; H, 3.45%; N, 17.50%.

Example 2 IR-spectrum: REE; 3560, 3410, 1723, 1545, 1495, 1430 1255, 1160, 1045, 1025, 940, 843, 772.

A solution This substance is administered by mouth in a dose of 5 to 30 mg. per kg. a day. In adults 0.3 mg, 0.5 mg. or 1 mg. of this substance is commonly used once or twice a day and the most common usage in adults is one gram of this substance once a day and in children it is 30 mg.

treatment with this substance is possible and there was found no appreciable untoward effects. The effect is rapid and almost twelve hours after the administration of this substance, the edematour swelling, heat and redness of joints or petechiae in rheumatic disorders disappear and the morning stiffness seen in rheumatoid arthritis shows a definite improvement.

The daily administration gives a favourable effect course of rheumatic disorders.

Examples 3 to 16 In a similar manner with Example 1 or 2, the following products were obtained from the following starting materials and isocyanates.

Example 3 on the UV-spectrum: Amax. 266.5 m,u (e=12,670).

Example 4 Starting material:

w CHOH N t 0 Isocyanate: methylisocyanate. Product:

5 t monoomrom \L o Melting point of the picrate of the product: 113-114 C. (from methanol).

Elemental analysis of the picrate: Calculated: C, 42.36%; H, 3.56%; N, 16.47%. Found: C, 41.98%;H, 3.87%; N, 16.40%.

UV-spectrum Amax. 266.5 mg (e=13,200).

Example 5 Example 6 Starting material:

CH2OTI Isocyanate. methylisocyanate. Product o 1 CH3 \N cHlodNHoEu Melting point: 136138 C. (from acetone).

Analysis of element: Calculated: C, 55.09%; H, 6.17%; N, 14.28%.

Found: C, 54.64%; H, 6.54%; N, 14.62%.

UV-spectrum: Amax. 260 n1,u(s=l1,840).

7 Example 7 N-isobutylcarb amate Example 8 Starting material: 2-pyridinemethanol N-oxide.

Isocyanate: allylisocyanate.

Product: 2-pyridinemethanol N-allylcarbamate (py) N-oxide.

Melting point: 9697 C. (from acetone-ether).

Analysis of elements: Calculated: C, 57.68%; H, 5.81%; N, 13.46%. Found: C, 57.62%; H, 5.80%; N, 13.49%.

Example 9 Starting material: 6-chloro-Z-pyridinemethanol. Isocyanate: methylisocyanate. Product: 6-chloro-2-pyridinemethanol N-methylcarbamate.

Melting point: 54-56 C. (from acetone).

Analysis of elements: Calculated: C, 47.96%; H, 4.53%; N, 17.67%. Found: C, 48.15%; H, 4.63%; N, 17.69%.

UV-spectrum: Amax. 268 m,u.(e=4400).

Example 10 Starting material: 6-cyano-2-pyridinemethanol.

Isocyanate: methylisocyanate.

Product: 6-cyano-2-pyridinemethanol N-methylcarbamate.

Melting point: 90-91 C. (from acetone-ether).

Analysis of elements: Calculated: C, 56.54%; H, 4.75%; N, 21.98%. Found: C, 56.09%; H, 4.63%; N, 21.70%. UV-spectrum: Amax. 270 mu(e=4400).

Example 11 Starting material: 6-cyano-2-pyridinemethanol.

Isocyanate: phenylisocyanate.

Product: 6-eyano-2-pyridinemethanol N-phenylcarbamate.

Melting point: 124-125 C. (from methanol).

Analysis of elements: Calculated: C, 66.39%; H, 4.38%; N, 16.59%. Found: C, 65.98%; H, 4.35%; N, 16.47%.

UV-spectrum: Mnax. 263.5 H1[L(=497o).

Example 12 Starting material:

HON=CH \N onion Isocyanate: methylisocyanate, Product:

H HON=CN CHzOGNHOHa Melting point: 127-128" C. (from methanol).

Analysis of element: Calculated: C, 51.67%; H, 5.30%; N, 20.09%. Found: C, 51.46%; H, 5.33%; N, 20.37%.

UV-spectrum: xmax. 244 mp.(e=4ll()).

Example 13 Starting material:

HO 0 cm-wmorr N Isocyanate: methylisocyanate.

Product:

O (:l) 1100c OHOONHGH N B a Melting point: 174-175 C. (from methanol).

Analysis of elements: Calculated: C, 51.42%; H, 4.80%; N, 13.33%. Found: C, 51.03%; H, 4.98%; N, 13.00%.

UV-spectrum: kmax. 224 mg, 262 In,u.(e=7020).

Example 14 Starting material:

HaCzOOG -CH2OH Isocyanate: methylisocyanate. Product:

II HaCaOOC CHzOGNHOHa N Melting point: 106-107 C. (from chloroform-ether). Analysis of elements: Calculated: C, 55.45%; H,

5.92%; N, 11.76%. Found: C, 55.72%; H, 6.20%;

UV-spectrum: Mnax. 269 m (e=10,650).

Example 15 Starting material:

rnNoc \N onion Isocyanate: methylisocyanate. Product:

H HzNOC N CHzOCNHCHa Melting point: 116-117" Analysis of elements: 5.30%; N, 20.09%.

UV-spectrum: )tmax.

C. (from acetone-ether). Calculated: C, 51.67%; H, Found: C, 51.29%; H, 5.69%; N,

Example 16 In a mixed solution of parts by volume of pyridine and '50 parts by volume of acetonitrile were added 15 parts of 2-pyridinemethanol N-oxide, 30 parts of S-ethyl- N-(Z-fu-rfuryl)-thiolcarbamate, and 15 parts of triethylamine. To the solution was added dropwise a solution of 26 parts of silver nitrate in 50 parts by volume of acetonitrile under cooling and stirring. After the completion of the addition the reaction mixture was allowed to stand at room temperature for 12 hours and then heated at 100 C. for 2 hours. After cooling, the mixture was diluted with chloroform and the precipitation was filtered 0E. The obtained residue was recrystallized from methanol to obtain 18 parts of Z-pyridinemethanol N(2-furfuryl)- carbamate (py)-N-ox-ide melting at -142 C. 1

Analysis of elements: Calculated: C, 58.06%; H,

9 4.87%; N, 11.29%. Found: C, 57.75%; H, 5.06%; N, 10.95%.

UV-spectrum: )tmax. 263 III/L (e=24,2).

Example 17 In a similar manner with Example 16, Z-pyridinemethanol N-oxide was reacted with S-ethyl-N-(3-picolyl)- thiolcarbamate to obtain 2-pyridinemethanol N-(3-picolyl)-carbamate (py)-N-oxide melting at '102-l04 C.

Analysis of elements: Calculated C, 60.22%; H, 5.05%; N, 16.21%. Found C, 59.87%; H, 5.39%; N, 15.99%.

UV-spectrum: xmax. 262 m (e=l5,100).

Example 18 A solution of 1 part of 2-pyridinemethanol N-oxide and 20 parts of nicotinyl azide in 200 parts by volume of pyridine was heated to 100 C. and was maintained at this temperature for 40 min. Then the reaction mixture was refluxed at 125 C. for hours. Pyridine was distilled off from the reaction mixture and the resulting residue was recrystallized from methanol-acetone to obtain 18 parts of 2-pyridinemethanol N-(3-pyridyl)-carbamate (py)-N-oxide having the melting point of 142- 143 C.

Analysis of elements: Calculated: C, 58.77%; H, 4.52%; N, 17.14%. Found: C, 60.03%; H, 4.85%; N, 16.87%.

UV-spectrum: Amax. 236

mp. $11,330), 264 m Example In a simliar manner with Example 21 In solution which was prepared by dissolving 4 parts of potassium metal in 100 parts of tert.-butanol under nitrogen, was added 12 parts of Z-pyridinemethanol N- oxide. The mixture was stirred for 2 hours and then added with 8 parts of ethylisothiocyanate. The reaction mixture was stirred for 12 hours at room temperature under nitrogen and then added with icewater, and neutralized with diluted hydrochloric acid. Most of the solvent was distilled off under reduced pressure, and the residue was extracted with chloroform. After removal of the solvent, the residue was recrystallized from acetone-isopropyl ether to obtain 10 parts of 2-pyridinemethanol N-ethylthiocarbamate (py)-N-oxide melting at 144-145 C.

Analysis of elements: Calculated: C, 50.94%; H, 5.70%; N, 13.20%. Found: C, 50.38%; H, 5.99%; N, 12.83%.

UV-spectrum: Amax. 247 m (e=36,700).

10 Examples 22 and 23 In a similar manner, the following products were obtained.

Example 22 Starting material: Z-pyridinemethanol N-oxide. Isothiocyanate: allylisothiocyanate.

Product: 2-pyridinemethanol N-allylthiocarbamate. Melting point: 96-97 C. (recrystallized from benzene Analysis of elements: Calculated: C, 53.57%; H, 5.39%; N, 12.50%. FoundzC, 53.40%; H, 5.38%; N, 12.47%. UV-spectrum: Amax. 249 m;t(e=20500).

Example 23 Starting material: 2-pyridinemethanol N-oxide.

Isothiocyanate; phenylisothiocyanate.

Product: 2-pyridinemethanol N-phenylthiocarbamate.

Melting point: 149-150 C. (recrystallized from methanol).

Analysis of elements: Calculated: C, 4.65%; N, 10.77%. Found: C, 60.21%; 10.35%.

59.99%; H, H, 4.72%; N,

Example 24 Calculated: C,

Example 25 at a temperature of 5 C. The reaction mixture was allowed to stand for 12 hours at 0 C., then the precipi- To a solution of 7.2 parts of 6-chloro-2-hydroxymethylpyridine in 50 parts by volume of pyridine was added dropwise 8 parts of phenylchloroformate at a temperature of 5 to 10 C. under stirring. After the completion of The crystalline precipitation was dissolved in 50 parts by volume of ethyl alcohol and was added with 10 parts by volume of 48% monomethylamine solution. The mixture was allowed to stand at room temperature for 12 hours, and then the solvent was distilled off under re- The residue was made alkaline with sodium hydroxide solution and was extracted with ether.

the either, the residue was from acetone to obtain 5.8 parts of 6-chloro-2-pyridinemethanol N-methylcarbamate melting at 54-55 C. Identification of the product with the sample obtained from Example 9 was performed by a mixed melting point duced pressure.

After removal of acid and was 10 parts of crystallized We claim:

and a comparison of their infrared spectra.

1. A compound having and 10% sodium hydroxide solution. The chloroform layer was separated, and The residue was treated with methanolic hydrochloric the solvent was distilled off.

crystallized from acetoneether to obtain 6-methyl-2-pyridinemethanol N-diethylcarbamate (py)-N-oxide melting at 122-l24 C.

the formula 10 Examples 27-31 H -cmoomv1u In a manner and yield similar to with Example 26, the N following products were obtained, f

Starting compound Arylchloroforniate Amine Product Example 27 Phenylchloroiormate (OHmNH (i t \N CEzOH N/'CH2OCN(CH3)2 J, o 3 Example 28 Plieuylchloroformatc CHgNlIz NC- i CHzOH NC- i CH OiDNHCH \N \N 2 3 J, 0 Example 29 p-Chlorophenylchloroformate Allylamine l t N CHzOH N CHzOCNHCaHa -L o 8 Example 30, (IIHZOH Phenylchlorolormate CHgNHz 0 ll (D1120 ONHOHa f o N -L 0 Example 31 Phenylchloroformate CHQNHQ 0 CHzOH H: memo NHCH:

N J N O -L 0 Example 32 wherein X is a member selected from the group consist- (lower) alkyl.

was heated for 9 hours at the solvent was distilled ofi remove the remaining water was added to the residue and made alkaline with potassium carbonate, and was extracted with chloroform. The solvent was distilled off, and the residue was treated with acetone. The obtained crystals were recrystallized from methanol-acetone to obtain 12 parts of Z-pyridinemethanol N-dimethylearbamate (py)-N-oxide melting at 106-105 C.

In an ethereal perphthalic acid Example 33 solution containing 11 parts of monowas dissolved 12 parts of 6-methyl-2- hydroxymethyl-pyridine N-diethylcarbamate. The solution was allowed to The precipitated crystalline substance was filtered, and the crystals were stirred with a mixture of chloroform stand at room temperature for 2 days.

ing of oxygen and ber selected from 2. A compound of sulfur and R and R are each a memthe group consisting of hydrogen and claim 4 having the formula 3. A compound of claim 4 having the formula l (lower)alk 0 Y 4. The compound of claim 4 which is Z-pyridiuemethanol N-methyl-carbamate (py)-N-oxide.

3,409,625 13 14 5. The compound of claim 4 which is Z-pyridine- OTHER REFERENCES methanol N'dimethyl'carbamate Culvenor: Reviews Pure and Applied Chemistry, vol. References Cited (81393920), 2(1 lljgtigginghem. Abstracts, vol. 53, Par. UNITED STATES PATENTS 5 Kametani et al.: Chem. Pharm. Bull. (Tokyo), v01. 6,

3,284,461 11/1966 Wilbert et a1 260 295 PP- 4617-72,

FOREIGN PATENTS HENRY R. JILES, Primary Examiner. 945,824 1/1964 Great Britain. A. ROTMAN, Assistant Examiner. 

